CuZn-SOD suppresses the bovine papillomavirus-induced proliferation of fibroblasts.

Eukaryotic cells continuously produce reactive oxygen species (ROS) and have mechanisms to control ROS levels. ROS have been shown to mediate cell proliferation and transformation. We studied the effect of CuZn-superoxide dismutase (CuZnSOD) on the focus-forming ability of bovine papillomavirus (BPV-1) wtDNA and hypertransforming mutant of its major oncoprotein E5, E5-17S.

Bovine papillomavirus type 1 oncoprotein E5 stimulates the utilization of superoxide radicals in the mouse fibroblast cell line C127.

The major transforming protein of bovine papillomavirus type 1 (BPV-1) is a small hydrophobic polypeptide, the E5 gene product, localized in the cellular membranes and modulating various pathways in the cell. Many studies have shown that reactive oxygen species (ROS) are essential in several biological processes, including cell transformation by oncogenes, but unregulated ROS are highly toxic to cells. We studied the effect of the bovine papillomavirus protein E5 and its mutants on the level of the superoxide radicals in the mouse fibroblast cell line C127.

Two antioxidative lactobacilli strains as promising probiotics.

Two antioxidative strains tentatively identified as Lactobacillus fermentum, E-3 and E-18, were isolated from intestinal microflora of a healthy child. Survival time of these strains in the presence of reactive oxygen species (ROS), like hydrogen peroxide, superoxide anions and hydroxyl radicals, was significantly increased compared with a non-antioxidative strain, and also was quite similar to a highly ROS resistant strain of Salmonella typhimurium. E-3 and E-8 contain a remarkable level of glutathione, express Mn-SOD, which is important for the prevention of lipid peroxidation, and secrete hydrogen peroxide.